Surface plasmon resonance (SPR) affinity biosensor relies on the measurement of the molecular binding induced refractive index changes and therefore it is label-free technology. Due to its high sensitivity, selectivity, and real-time measurement capability, SPR biosensor has become the technology of choice for researchers within the pharmaceutical and biomedical industry to characterize molecular interaction kinetic, thermodynamics, and concentration. SPR biosensors can support an incredible range of applications from qualitative binding to high resolution kinetic analysis. Nearly any interaction involving biological systems including low molecular weight components, proteins, nucleic acids, antibody, and even lipid surface environments are amenable to these instruments.
SPR biosensors are based on the measurement of refractive index of the fluid under test. The refractive index is indicated by a dark bar in a light band detected by a detector such as CMOS image sensor. The position of the dark bar indicates the SPR resonance angle, which in turn, indicates the refractive index of the fluid under test. To perform reliable measurement, the relation between the position of the dark bar and the SPR resonance angle must be calibrated. The ideal situation is the calibration is provided for each measurement, such that an auto-calibration SPR biosensor can be realized.
The SPR based technology continues to expand and improve to become an indispensable analytical tool in biomedical research. Although a tremendous progress has been made in modern days SPR equipment, simple and precise detection method is still in demand. Accordingly, auto-calibration SPR biosensor is still in demand.
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